Sidekiq is a simple and efficient background processing tool for Ruby on Rails apps. You should use it for tasks that take too long to put in a controller or tasks that need to run on a schedule. Common examples are sending emails, generating pdf’s and connecting to other services through an API.
Like all things in IT, Sidekiq can crash, get slow or need more capacity. And for some applications that really should not happen. Because nobody directly interacts with Sidekiq it can be a long time before someone notices that something is wrong.
A good solution to quickly restart (kick, hehe) a crashed Sidekiq is to have a watchdog on the server. Both systemd and upstart can do that for you, and there are lot of other watchdogs you can install. But I’d still like to know something happend, or when an edge case happens where the watchdog cannot fix it. The solution? Monitoring Sidekiq from the outside.